Perhaps you should try some spelling variations:
"python missing data snippets" » "python using data snippets"
"locating bug core snippets" » "locating bug code snippets"
"xa dong he snippets" » "xa dong code snippets", "ha dong he snippets", "van dong he snippets", "lao dong he snippets", "xa dong che snippets", "xa dung he snippets", "xa dong ha snippets"

Try widening your search to All Fields.

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: (((("xa dong he snippets") or ("python missing data snippets"))) or ("locating bug core snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("xa dong he snippets") OR ("python missing data snippets"))) OR ("locating bug core snippets")).
• Removing quotes may allow a broader search: (((( xa dong he snippets ) or ( python missing data snippets ))) or ( locating bug core snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("xa dong he snippets") or ("python missing data snippets"))) or ("locating bug core snippets"))*.